Oxidation
of Organosolv Lignin in a
Novel Surfactant-free Microemulsion Reactor
Juanhua Kong, Lixia Li, Xin Luo, Qiang Zeng, Xiumin Chen, Zhenping Cai,
Jinxing Long, Sijie Liu* and Xuehui Li*
School of Chemistry and Chemical Engineering, State Key Laboratory of
Pulp and Paper Engineering, South China University of Technology,
Guangzhou, 510640, China.
Hongyan He
Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of
Process Engineering, Chinese Academy of Sciences, Beijing, 100190,
China.
Yingying Wang
South China Advanced Institute for Soft Matter Science and Technology,
South China University of Technology, Guangzhou, 510640, China.
Lignin is considered as a promising substitute for fossil
resources, but the efficient conversion of the lignin remains a huge
challenge due to its structural complexity and immiscibility with
typical solvents. Herein, a series of surfactant-free microemulsion
reactors comprised of octane, water and n-propanol were designed and
their corresponding phase behaviors alongside their ability to intensify
oxidative depolymerization of lignin was explored. Experimental results
show that the phenolic monomer yield improves substantially (40-500
wt.%) when the novel microemulsion systems are employed by comparison
with processes performed in a single solvent. Detailed characterizations
also suggest that the above intensification is rationalized by the
solubilization effect of the microemulsion system, which arise as a
consequence of directional aggregation of lignin at the microemulsion
interface.